国家地理标志保护产品——北乡马蹄

为了提高北乡马蹄的产量和质量，使北乡马蹄创造出更大的经济价值，为当地的农户创造更高的收益，通过了解当地的情况，阐述了北乡马蹄的基本特征及种植现状；结合现代农业技术，总结出北乡马蹄高效栽培技术要点，包括种球选择、育秧、定植、田间管理、病虫害防治及采收等。     

中国板栗238份品种（系）叶片形态、解剖结构及其抗旱性评价

采用多功能图像分析法、冷冻切片法和指甲油印记法，对238份板栗品种（系）叶片的形态、解剖结构及气孔特征进行了观察测量，运用变异系数、主成分分析对33项指标进行了筛选，后运用隶属函数法进行抗旱性综合评价。结果表明：（1）238份板栗品种（系）33项指标中除上表皮角质层厚度、上表皮细胞宽度、第一层栅栏组织细胞密度、第一层栅栏组织细胞宽、下表皮细胞宽度和下表皮角质层厚等6项指标的变异系数小于10%，各品种系（间）差异较小外，其余27项指标的变异系数均大于10%，在各品种（系）间差异较大；经主成分分析从27项指标中筛选出10项作为238份板栗品种（系）抗旱性综合评价的典型指标。（2）利用隶属函数分析将238份品种（系）划分为4类：第Ⅰ类包括31个品种（系），平均隶属值为0.60 ~ 0.80，抗旱性极强；第Ⅱ类包括48个品种（系），平均隶属值为0.50 ~ 0.59，抗旱性强；第Ⅲ类包括84个品种（系），平均隶属值为0.30 ~ 0.49，抗旱性中；第Ⅳ类包括75个品种（系），平均隶属值为0.20 ~ 0.29，抗旱性弱。     

大粒板栗新品种‘秦栗2号’

（西北农林科技大学林学院，陕西杨凌 712100）     

水分对栗钙土理化性质及杨树生长的影响

采用野外调查和室内测试相结合的方法,研究了水分对栗钙土理化性质和杨树生长的影响.结果表明:由于过水林地比未过水林地具有较低的容重和土壤硬度、较高的土壤持水能力以及较高的有机质、全氮、全磷和有效氮含量,使得过水林地上杨树人工林的直径、树高和材积生长量、各级根系长度、根系总长度和根系总生物量整体上超过来过水林地.     

Identification and pathogenicity of Cryphonectriaceae species associated with chestnut canker in China

Cryphonectriaceae species cause serious canker diseases on chestnut, oak and eucalypt trees. Recently, canker symptoms with typical orange fruiting bodies were observed on Chinese chestnut and oak trees in Hebei, Hubei, Shaanxi and Shandong Provinces in China. In the present study, isolates of these fungi were identified based on phylogenetic and morphological evidence, and their pathogenicities were tested on detached chestnut (Castanea mollissima) branches. DNA sequence comparisons of the internal transcribed spacer (ITS) regions and two regions of β-tubulin (TUB1/TUB2) indicate that these isolates represent five species in the Cryphonectriaceae, viz. Cryphonectria japonica, Cryphonectria parasitica, Aurantiosacculus castaneae sp. nov., Cryphonectria neoparasitica sp. nov. and Endothia chinensis sp. nov. The sexual morph of Aurantiosacculus is discovered for the first time and can be distinguished from the other genera in Cryphonectriaceae by dark brown ascospores and tubiform appendages at both ends. Cryphonectria neoparasitica sp. nov. is different from the other Cryphonectria species by its aseptate ascospores. Endothia chinensis sp. nov. is the sole species in Endothia infecting the host genus Castanea. Additionally, it is much smaller than E. gyrosa and narrower than E. singularis in ascospores. The inoculation results showed that these five Cryphonectriaceae fungi isolated from chestnut or oak are all pathogenic to tested chestnut branches. Cryphonectria parasitica appears to be the most aggressive fungus, followed by C. neoparasitica sp. nov., C. japonica, E. chinensis sp. nov. and A. castaneae sp. nov.     

放牧压力对草原砂质栗钙土微生物量C,N,P影响的研究

对不同放牧压力下草原砂质栗钙土微生物量C、N、P进行较为系统地研究。结果表明：就土壤原土来看,随着放牧压力的增大,土壤微生物量C,N先增加后减少;土壤微生物量C在放牧率2.67只羊/hm2时相对较高,微生物量P随着放牧压力的增大逐渐降低。     

High vegetative compatibility diversity of Cryphonectria parasitica infecting sweet chestnut (Castanea sativa) in Britain indicates multiple pathogen introductions

Chestnut blight, caused by Cryphonectria parasitica, was identified in Devon, UK, in December 2016. Intensive surveys detected the disease at further sites in Devon (seven), Berkshire (one), Dorset (one), Derbyshire (four) and a cluster of eight sites in southeast London. Over 570 survey samples were tested, and 227 were positive for C. parasitica by isolation and real-time PCR. A total of 227 isolates were tested for mating type, and 197 screened for vegetative compatibility group (VCG) and compared with VCGs known from mainland Europe. The same isolates were also screened for the presence of Cryphonectria hypovirus 1 (CHV-1). Eleven VCGs were identified within the UK population. Five corresponded to already known European VCGs but six were unique. The European VCGs mainly came from the Devon, Dorset, Berkshire and Derbyshire disease outbreaks, whilst unique VCGs were almost exclusively from the southeast London cluster. Both mating types were detected, but only one mating type was present at each site, with the exception of a single Devon site. Perithecia of C. parasitica were never observed at any site. CHV-1 was found in seven isolates from three different locations and was always subtype-I, which has limited hypovirulence. Therefore, although CHV-1 is associated with C. parasitica at some outbreaks, it probably has limited impact on virulence. The diversity of VCGs and their distribution at outbreak sites, together with findings of CHV-1, suggests C. parasitica has been introduced to the UK multiple times over at least two decades through international plant trade.     

嫩板栗脱蒲试验台的设计与试验

基于国内板栗脱蒲机,针对六至八成熟的嫩板栗存在的机器脱蒲分离率低、适应性差、容易损伤及嫩板栗成熟周期短等问题,设计了一种嫩板栗脱蒲试验台。该试验台选用柔性挤压的脱蒲方法,利用旋转的脱蒲滚子与栅栏挤压杆相互揉搓挤压作用对嫩板栗进行脱蒲。该试验台的脱蒲滚子及栅栏挤压杆均可更换。通过试验对比,可以分析出不同类型的脱蒲滚子与挤压杆对板栗脱蒲的影响。此外,本试验台配备了变频器,可以在不更换电动机的前提下,将电动机的转速进行随意调节。测试结果表明:该试验台不同的脱蒲滚子、栅栏挤压杆及主轴的旋转速度都会对嫩板栗的脱蒲造成不同的影响,根据不同的数据可以为嫩板栗脱蒲机械提供不同的改善方案及理论依据。     

板栗新品种‘燕秋’

‘燕秋’是在河北省青龙县板栗实生资源调查中选出的优良新品种。具有耐短截、丰产、优质等优良特性。9月上旬成熟。坚果整齐度高,单果质量8.3 g,红褐色,油亮,绒毛稀疏,底座中;果肉乳黄色,炒食香、甜、糯俱佳,适宜糖炒。单株产量达8.1 kg,折合产量4 028.3 kg·hm~(-2)。适宜在燕山板栗主栽区的山地、丘陵栽培。授粉树配置以‘燕山早丰’、‘燕龙’、‘燕奎’为宜。